Monahan K, et al., Archiv Surg S Educ 2021, 3: 017
DOI: 10.24966/ASSE-3126/100017
HSOA Archives of Surgery and Surgical Education Research Article
Hemiepiphysiodesis via the Bowen Method for Genu Valgum in Adolescents Kevin Monahan, Hanel Watkins Eberly*, Tommy Pan, John Anagnostakos, Andrew Konopitski and William L Hennrikus Penn State College of Medicine, Hershey, Pennsylvania, USA
Abstract Objective: Surgical techniques using bone blocks, screws, plates and staples have been described to biologically manipulate the growth plate to correct leg length inequality, genu varum and genu valgum. This study aimed to evaluate adolescents undergoing percutaneous hemiepiphysiodesis for correction of genu valgum. Methods: An IRB-approved retrospective review was conducted for 26 patients who underwent percutaneous hemiepiphysiodesis for genu valgum correction. Hemiepiphysiodesis, was performed at the medial physis of the tibia +/- femur. Patients were followed for measurement of Intermalleolar (IM) gap and Femorotibial (FT) angle correction. Seventeen females and 9 males were studied. Results: The average age at time of surgery was 12.6 years. The average net IM distance and FT angle correction was 9.9 cm and 10.1º. Fourteen patients (54%) underwent femoral and tibial growth plate manipulation; correction rate for IM distance was 0.7cm/month and FT angle was 1.1º/month. Ten patients (38%) underwent tibial growth plate manipulation; correction rate for IM distance was 0.7 cm/month and FT angle was 1.3º/month. Patients with closed Distal Phalanx (DP) growth plates on bone age radiographs, indicating pending skeletal maturity, were more likely to undergo FT physis manipulation. Conclusion: Percutaneous hemiepiphysiodesis is a safe and effective method to correct genu valgum. The success rate was 92%. No patients required completion of the hemiepiphysiodesis. The timing of the procedure is based on skeletal maturity by bone age.
*Corresponding author: Hanel Watkins Eberly, Penn State College of Medicine, Hershey, Pennsylvania, USA, Tel: +1 6267716948; Email: haneljune@gmail.com / hwatkins@pennstatehealth.psu.edu Citation: Monahan K, Eberly HW, Pan T, Anagnostakos J, Konopitski A, et al. (2021) Hemiepiphysiodesis via the Bowen Method for Genu Valgum in Adolescents. Archiv Surg S Educ 3: 017. Received: March 21, 2021; Accepted: March 31, 2021; Published: April 09, 2021 Copyright: © 2021 Monahan K, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Keywords: Genu valgum; Pediatric; Percutaneous
Hemiepiphysiodesis;
Orthopedics;
Introduction Genu valgum is part of a normal physiologic process in children. During development, the Femorotibial (FT) angle progresses in a varus to valgus fashion. Before 1 year, an infant may reach up to 15º of varus. At 2 years of age, children approach neutral. By 3 years old, children can progress to maximum valgus before spontaneously correcting to approximately 6º before age seven [1]. Persistent genu valgum may be unilateral or bilateral in nature, with persistent genu valgum most often bilateral in nature. Etiologies such as growth plate disorders, skeletal dysplasias and idiopathic usually present bilaterally. Trauma to the knee or infections can lead to unilateral genu valgum. Indications for surgery have included: 1) unacceptable cosmesis; 2) genu valgum >15º after age seven; 3) asymmetry; 4) Intermalleolar (IM) distance greater than 7.5cm; 5) altered gait; 6) pain and 7) decreased participation in physical activity [2,3]. Various surgical approaches have been described in the literature as effective treatments for patients with angular deformities of the lower extremity [4-9]. Physeal manipulation has the advantage of decreased morbidity when compared to more invasive methods such as an osteotomy [10,11]. Phemister described growth arrest by physeal manipulation in 1933 by rotation of the epiphyseal plate 90° to create a bony bridge [12]. Blount and Clarke described controlling physeal growth in 1949 through epiphyseal stapling [13]. Temporary hemiepiphysiodesis can be obtained using tension-band plating, percutaneous transphyseal screws and stapling [14-16]. A method described by Bowen, percutaneous hemiepiphysiodesis, however, offers the advantage of minimally invasive surgery without return to the or for hardware removal. In the Bowen technique, a selected area of the growth plate is identified and ablated leading to growth inhibition and gradual limb correction [17,18]. Timing of when to perform hemiepiphysiodesis for optimal physeal ablation and deformity correction is key to successful outcome and is guided by bone age radiographs [19-21]. In this study, we analyzed the outcomes of twenty-six children with idiopathic genu valgum undergoing percutaneous hemiepiphysiodesis of the proximal tibia or proximal tibia and distal femur in order to report outcomes, safety and efficacy.
Methods This study was approved by the medical school Institutional Review Board (IRB). A retrospective study was conducted of 26 patients and 51 limbs with idiopathic genu valgum between the years of 20062017. Clinical patient demographics recorded included: gender, age and chief complaint. Additional radiographic demographics recorded were: bone age radiographs of open or closed Distal Phalanx (DP) joint (Figure 1A and 1B), location of hemiepiphysiodesis and initial